Effects of zeolite and silica fume substitution on the microstructure and mechanical properties of mortar at high temperatures

Abstract

The exposure of concrete to high temperatures leads to mechanical and chemical changes, and the performance of concrete is extremely dependent on its mortar specification. In this study, the compressive and tensile strength of mortar in a temperature range of 28–800 °C is investigated in hot conditions. The microstructure characterization is examined by X-ray diffraction test, thermal gravity analysis, and scanning electronic microscopy test. To minimize the environmental impacts of cement consumption, the possibility of partial replacement of cement with pozzolans is investigated. The results indicate that partial replacement of cement with zeolite and silica fume in the mixing plan of the concrete structure exposed to high-temperature meet both engineering and environmental consideration. Furthermore, the XRD and the TGA results provide valuable information about the prediction of the order of strength and the temperature history of the concrete members. The results pave the way for a better understanding of the high-temperature behavior of pozzolanic mortars.